How Astronomers Used a Natural Phenomenon to Spot the Faintest Object Ever

NASA’s Hubble and Spitzer space telescopes are impressive pieces of hardware. But even they need a little help from time to time. Astronomers used the pair of telescopes to help spot an object dubbed Tayna. It means ‘first-born’ in Aymara, a language spoken in the Andes and Altiplano regions of South America.

Tayna lives up to its meaning. This galaxy existed just 400 million years after the big bang. I know 400 million years sounds like a lot. But our universe is around 12-14 billion years old. 400 million years is nothing.

To spot Tayna, astronomers used a phenomenon called gravitational lensing. It’s basically a magnifying glass in space. Here’s how it works. Einstein’s theory of general relativity tells us mass bends light. Now our universe is home to a lot of massive objects. And when a huge object lines up just right (between the target galaxy and Earth), it bends the light from the target galaxy and magnifies it. The image below from NASA perfectly illustrates how it works.

In Tayna’s case, astronomers pointed the telescopes at MACS J0414.1-2403. It’s a giant cluster of galaxies that weigh as much as a “million billion suns.” With that kind of mass, Tayna appears about 20 times brighter than normal thanks to gravitational lensing.

“Thanks to this detection, the team has been able to study for the first time the properties of extremely faint objects formed not long after the big bang,” says lead author Leopoldo Infante.

What astronomers know about Tayna

The astronomers say Tayna is comparable in size to the Large Magellanic Cloud (LMC). But is believed to be making stars at a rate 10 times faster than the LMC. Or was. After all, we are looking at Tayna as it was billions of years ago.

How did astronomers figure out its distance (and age)? By looking at its color. The astronomers combined Hubble and Spitzer observations to form a color profile. As the universe expands, light from distant galaxies is stretched with increasing distance. This makes them appear redder. It’s a phenomenon known as redshift.

Tayna is one of 22 young galaxies recently discovered shortly after the big bang. These discoveries suggest there are many more galaxies waiting to be discovered. Astronomers just need the tools to do it. They won’t be waiting much longer for new tools. The James Webb Space Telescope just had its first mirror installed. It’s slated for launch in late 2018.